Stock Width of a SACHS 3x7 hub.

Discussion in 'Cycling Equipment' started by pureheart@pacbell.net, Feb 23, 2008.

  1. I got a Sachs 3x7 off ebay.
    In building it up, (Mavic 261 & DT straight guage spokes) the usual
    way, I am stunned to see my dishing so far off.

    I'm about 75% tensioned already and I find that I've got 12mm of
    dishing yet to do! (ie, have to pull it over 6mm...I don't think that
    will be possible.

    My locknut to locknut distance is 130mm. Is this the stock width for
    this hub? If it's actually supposed to be 135, then a 5mm spacer will
    go a long way towards making me feel a whole lot better.

    As it is now, this hub does not appear to have been messed with in any
    way and the 130mm looks original....anyone know for certain?

    Pureheart in
    Aptos, CA
     
    Tags:


  2. A Muzi

    A Muzi Guest

    pureheart@pacbell.net wrote:
    > I got a Sachs 3x7 off ebay.
    > In building it up, (Mavic 261 & DT straight guage spokes) the usual
    > way, I am stunned to see my dishing so far off.
    >
    > I'm about 75% tensioned already and I find that I've got 12mm of
    > dishing yet to do! (ie, have to pull it over 6mm...I don't think that
    > will be possible.
    >
    > My locknut to locknut distance is 130mm. Is this the stock width for
    > this hub? If it's actually supposed to be 135, then a 5mm spacer will
    > go a long way towards making me feel a whole lot better.
    >
    > As it is now, this hub does not appear to have been messed with in any
    > way and the 130mm looks original....anyone know for certain?


    Sounds about right. New Bianchis with 3x7 have 110kg left and 125kg
    right tension. Slack those left spokes and center it before bringing the
    tension up. You did lube the nipples, right?
    --
    Andrew Muzi
    www.yellowjersey.org
    Open every day since 1 April, 1971
     
  3. Tom Sherman

    Tom Sherman Guest

    Andrew Muzi wrote:
    > pureheart@pacbell.net wrote:
    >> I got a Sachs 3x7 off ebay.
    >> In building it up, (Mavic 261 & DT straight guage spokes) the usual
    >> way, I am stunned to see my dishing so far off.
    >>
    >> I'm about 75% tensioned already and I find that I've got 12mm of
    >> dishing yet to do! (ie, have to pull it over 6mm...I don't think that
    >> will be possible.
    >>
    >> My locknut to locknut distance is 130mm. Is this the stock width for
    >> this hub? If it's actually supposed to be 135, then a 5mm spacer will
    >> go a long way towards making me feel a whole lot better.
    >>
    >> As it is now, this hub does not appear to have been messed with in any
    >> way and the 130mm looks original....anyone know for certain?

    >
    > Sounds about right. New Bianchis with 3x7 have 110kg left and 125kg
    > right tension. Slack those left spokes and center it before bringing the
    > tension up. You did lube the nipples, right?


    Are new 3x7 hubs available other than NOS? SRAM only lists 3x8 and 3x9
    versions of the DualDrive II on their web page [1].

    Does the DualDrive hub differ from the older Torpedo based 3x7 in flange
    width and diameter?

    [1] Sorry, no URL due to SRAM's egregious use of Flash®. Arrrrgh!

    --
    Tom Sherman - Holstein-Friesland Bovinia
    The weather is here, wish you were beautiful
     
  4. A Muzi

    A Muzi Guest

    >> pureheart@pacbell.net wrote:
    >>> I got a Sachs 3x7 off ebay.
    >>> In building it up, (Mavic 261 & DT straight guage spokes) the usual
    >>> way, I am stunned to see my dishing so far off.
    >>> I'm about 75% tensioned already and I find that I've got 12mm of
    >>> dishing yet to do! (ie, have to pull it over 6mm...I don't think that
    >>> will be possible.
    >>> My locknut to locknut distance is 130mm. Is this the stock width for
    >>> this hub? If it's actually supposed to be 135, then a 5mm spacer will
    >>> go a long way towards making me feel a whole lot better.
    >>> As it is now, this hub does not appear to have been messed with in any
    >>> way and the 130mm looks original....anyone know for certain?


    > Andrew Muzi wrote:
    >> Sounds about right. New Bianchis with 3x7 have 110kg left and 125kg
    >> right tension. Slack those left spokes and center it before bringing
    >> the tension up. You did lube the nipples, right?


    Tom Sherman wrote:
    > Are new 3x7 hubs available other than NOS? SRAM only lists 3x8 and 3x9
    > versions of the DualDrive II on their web page [1].
    > Does the DualDrive hub differ from the older Torpedo based 3x7 in flange
    > width and diameter?
    > [1] Sorry, no URL due to SRAM's egregious use of Flash®. Arrrrgh!


    Gee, I have no idea. 3x7 & 3x8 DualDrive are listed at distributors, no
    3x9 listings[1]. The 3x7 (8, 9?) isn't setting the world afire as far as
    aftermarket sales go.

    But OP seemed unclear on typical left-right tension differences and
    there were new 3x7 Bianchis across the room, so I just picked up a
    tensiometer[2] and measured one.

    footnote section for Tom:
    [1] A 3x8 can take a 9 cassette of course so this is trivial.
    [2] SpelChek says this is not a word.
    --
    Andrew Muzi
    www.yellowjersey.org
    Open every day since 1 April, 1971
     
  5. Tom Sherman

    Tom Sherman Guest

    Andrew Muzi wrote:
    > [...]
    >> Andrew Muzi wrote:
    >>> Sounds about right. New Bianchis with 3x7 have 110kg left and 125kg
    >>> right tension. Slack those left spokes and center it before bringing
    >>> the tension up. You did lube the nipples, right?

    >
    > Tom Sherman wrote:
    >> Are new 3x7 hubs available other than NOS? SRAM only lists 3x8 and 3x9
    >> versions of the DualDrive II on their web page [1].
    >> Does the DualDrive hub differ from the older Torpedo based 3x7 in
    >> flange width and diameter?
    >> [1] Sorry, no URL due to SRAM's egregious use of Flash®. Arrrrgh!

    >
    > Gee, I have no idea. 3x7 & 3x8 DualDrive are listed at distributors, no
    > 3x9 listings[1].


    Odd, since the SRAM website used to list 3x7, 3x8 and 3x9 versions of
    the DualDrive, but now only lists 3x8 and 3x9 versions of the "DualDrive
    II".

    > The 3x7 (8, 9?) isn't setting the world afire as far as
    > aftermarket sales go.
    >

    I imagine most DualDrive hubs are sold OEM. Only a few weirdos are out
    there that would combine such a hub with a triple crank. Oh wait, I
    resemble that remark.

    > But OP seemed unclear on typical left-right tension differences and
    > there were new 3x7 Bianchis across the room, so I just picked up a
    > tensiometer[2] and measured one.
    >
    > footnote section for Tom:
    > [1] A 3x8 can take a 9 cassette of course so this is trivial.


    SRAM has integrated shifters with a twist-grip for the derailer and a
    thumb lever for the hub gears for DualDrive II (at least the website
    says so).

    > [2] SpelChek says this is not a word.


    Wikipedia says "A tensiometer is a device used to determine matric water
    potential Ψm (soil moisture tension) in the vadose zone."

    Fans of 1950's marketing can call it a Tension-O-Meter.

    --
    Tom Sherman - Holstein-Friesland Bovinia
    The weather is here, wish you were beautiful
     
  6. On Feb 23, 4:56 pm, A Muzi <a...@yellowjersey.org> wrote:
    > purehe...@pacbell.net wrote:


    <snip>
    > > My locknut to locknut distance is 130mm. Is this the stock width for
    > > this hub? If it's actually supposed to be 135, then a 5mm spacer will
    > > go a long way towards making me feel a whole lot better.

    >
    > > As it is now, this hub does not appear to have been messed with in any
    > > way and the 130mm looks original....anyone know for certain?

    >
    > Sounds about right. New Bianchis with 3x7 have 110kg left and 125kg
    > right tension. Slack those left spokes and center it before bringing the
    > tension up. You did lube the nipples, right?
    > --

    <snip sig>

    Sure did. And spoke-prep on the spokes (cuz I happen to have some).
    I found some of the new dual-drives. The bodies look similar to what I
    have (Torpedo-ish) and they all list a 135mm width on the ones I've
    seen which gives me even more pause.

    I'm going to hold off and make sure before I "slack and center" as you
    suggest. Thanks for the help.

    Pureheart
    >
     
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